Fire protective system



Feb. 6, 1934. B. RICHARDS v 1,945,620

FIRE PROTECTIVE SYSTEM Filed 001;. l, 1927 E 7 k d i a 5 43 v8 30 I 7 i O7 Z36 wjemwifl Richards a'tio rweya Patented Feb. 6, 1934 i-JNETED TATES PATENT oFFicE' Automatic Sprinkler Company,

Cleveland,

Ohio, a corporation of Delaware Application October 1, 1927.

1- Claimr This invention relates to improvements in fire protective systems. More especially it relates to automatic sprinkler systems, for example a dry pipe sprinkler system having closed heads on dis- 5 tributing pipes normally filled with air under pressure; and it provides for such to be changed automatically to a wet pipe system and for an alarm to be sounded immediately before the opening of any sprinkler head.

In the ordinary dry pipe system, air under considerable pressure acts upon a dry pipe valve to hold back a supply of liquid, usually water, until such time as a sprinkler head opened by abnornally high temperature permits the air to eslE cape. However, the escaping air blast may aid rather than hinder the spread of flames. Also, the delay that must ensue between the opening of a sprinkler head and the arrival of water at that head is recognized as a dangerous factor, the reduction of which to permissible limits involves sub-division of systems and multiplication of expensive parts. Moreover, since the heads are designed to remain closed until a temperature of approximately 160 is reached, in order to prevent an unwarranted opening of a sprinkler with resulting damage by water where no actual fire exists, it is possible for the sprinklers rise of temperature to that height to be so deferred by air currents or other causes that an incipient fire makes considerable progress before the sprinklers opening occurs. During this period of delay, no alarm or signal is given by such a system because the alarm apparatus is dependent for its actuation upon the opening of the dry ipe valve. Where two or more dry pipe valves are fed from the same main, there is also danger, in some cases, that the discharge pressure in the systems first opened will be greatly reduced for a time, because the opening of the neighboring dry pipe valve temporarily provides such a vast outlet for the water in the main.

Therefore in planning dry pipe systems the period of elapsed time between the breaking out of the fire and the beginning and maintenance of full discharge of water upon it has long been a matter of concern; for the prompt throwing of a few gallons upon an incipient fire is more effective, and means far less damage, than torrents poured in when a spreading fire has gotten well under way.

It is an object of this invention to have an alarm sounded or a signal transmitted to a distant station, promptly upon the occurrence of a fire and prior to the opening of a sprinkler head.

Another object is to provide for the release of Serial No. 223,406

the greater part of this air at a place remote from the fire, thus preventing its giving aid to the flames or causing them to spread.

These objects, and other advantages incident to the invention, some of which are mentioned hereinafter, are attained by providing, in conjunction with a dry pipe system having the usual sprinkler heads, auxiliary means operated by change of temperature and preferably comprising a series of devices, called rate-of-rise devices, which are actuated by abnormal rapidity of rise of temperature, rather than by rise of temperature to any predetermined degree. These devices are distributed about the risk in proximity to the sprinkler heads, or in any locations where a particular fire hazard is thought to exist, and are operatively connected (for example, electrically or pneumatically) with the system so that upon being actuated by an abnormally rapid rise of temperature they effect an opening of that valve in the dry pipe system which is holding back the fire extinguishing medium. The rate-of-rise devices operate a release valve with outlet from these lines on the air side of the dry pipe valve, preferably from the riser. When a sufficiently so rapid rise of temperature occurs, the rate-of-rise device detecting it brings about an opening of the release valve, whereupon air escapes rapidly from the riser (through an opening of much greater capacity than a sprinkler nozzle) until the 35 dry pipe valve opens and lets water fill the distributing system and close the release valve, while every sprinkler head, in the ordinary case, remains still unopened. The distributing pipes being thus preliminarily filled with water,ex- 9Q cept for perhaps a small section in each final branch where remaining air is trapped,eifective Water discharge begins as soon as any sprinkler opens, withno delay and no preliminary air blast; while if the fire be extinguished by 5 human agency before a sprinkler opens there is no water damage by fiow from sprinkler head.

The air escaping through the said release valve from a high pressure system may sound an alarm or transmit a signal, before any sprinkler head is opened.

It is intended that the patent shall cover by suitable expression in the appended claim whatever features of patentable novelty exist in the invention disclosed.

In the accompanying drawing:

Figure 1 is an elevation, somewhat diagrammatic, of a building having a dry pipe sprinkler system with air under pressure as is ordinary, but also embodying the present invention;

Figure 2 is an elevation, with parts in section, and somewhat diagrammatic, of details of the system of Figure 1;

Figrue 3 is an elevation, partly in section, showing details of the relief valve of Figure 2.

Referring more particularly to the drawing, there is shown in Figures 1 and 2, a building equipped with the usual dry pipe sprinkler system which comprises a lead-in 10 from a water main to a dry pipe valve 12 and a riser 14, with distributing pipes 16 running throughout the risk and having automatic sprinkler heads 18. The system beyond the dry pipe valve is filled with air under pressure, say of two or three atmospheres, to maintain the dry pipe valve closed against the ever pressing force of water in the main.

The present invention provides a release valve 20 in the riser 14, with relatively large vent, so that compressed air in the system escapes much more rapidly than through an open sprinkler. When the system is charged awaiting action, the valve 20 is held closed against its seat by a valve lever 22 pressing on its stem which comprises two oppositely threaded sections 20 and 20 joined by a nut 20 so that the length of the stem can be adjusted to insure a tight seating of the valve 20 The lever 22 is latched in the valve-closed position by any suitable means which can release it under control of a rate-of-rise device. The means illustrated is a keeper 24 on the short arm of a lever 24 whose long arm carries a weight 26, which tends to move the keeper to release the valve. But the weight 26 is, when the apparatus is set and waiting for action, upheld by a tight chain 28 engaged on the short arm hook of a third lever 30 which projects from within a control box 32. This third lever, has its long arm engaging a small knife-edged strut 34 that extends to a fourth lever 36, the strut being placed a substantial distance below and a little to one side of the pivot of lever 36, with its line of force close to passing through the pivot, but a little on the side thereof whereon the transmitted force of weight 26 tends to turn lever 36 about this pivot and Dresses it tightly against a stop pin 38. At the end of the long arm of lever 36 is some suitable form of device for releasing this lever so that the weight 26 can fall and unlatch lever 22. Devices suitable for this are already well known in the industry, such for example as the Lowe release operating pneumatically on a rate-of-rise principle; and the faero-thermostatic system operating pneumatically upon the attaining of a fixed temperature; and pure electrical systems, which may work through relays to a releasing solenoid. In the present'specification, for illustrating this part of the apparatus, there is shown a combination of electric and pneumatic elements, in which a leverreleasing solenoid 40 is actuated by any one of a number of heat responsive devices 42 distributed at selected positions about the risk. Each device 42 may be constructed upon well known principles so that it will be actuated by expansion of air in the device 42, in case a rate as great, for example, as 15 per minute occurs; and so that its effect, when actuated, is to break a circuit between two wires 20, to, which extend from the solenoid 40 through the various rate-of-rise devices 42, in series. The consequent de-energization of the solenoid permits its armature core to fall and thus to deliver a blow upon the end of lever 30 which swings the strut 34 under the dead centre to the other side of the pivot 36 The weight 26 can then fall so as to unlatch lever 22. Air in the distributing pipes thereupon opens the valve 20 and escapes through pipe 44 into a float chamber 46, in which is a suitable ball float 48, and passes out through an opening 46 at the top, and thence escapes through a connection 50 into pipe 52 leading to a pressure responsive device 54, motor alarm 56 and vent 56 Thus it may both sound the alarm gong 58 and may close a circuit through wires 60 to give a signal at a distant station, as for example in the office of a fire protective association. Being thus responsive to the mere rate of change of temperature such a device responds to the breaking out of a fire much sooner than would a sprinkler head near the same location which must wait until the temperature has risen to a predetermined degree.

The rapid escape of the air through the release valve 20 lets the dry pipe valve 12 quickly open for water from the main to rush into the distributing system to the still closed sprinkler heads 18. Water which then flows through the release valve 20 into the chamber 46 floats the ball to the top of the chamber and so closes the discharge opening 46 The pipe 62 leading from the intermediate chamber of the dry pipe valve, to the usual ball drip 64 continues through a check valve 66 into pipe 52. When air enters pipe 52 via the release valve the check valve is seated, closing the pipe 62, but upon the opening of the dry pipe valve 12 water flows through pipe 62, closing the drip 64 and opening the check valve 66 to the vent 56 and thus continues the alarm and signal after the ball float 48 has closed the opening 46.

In the system herein disclosed the valve governing the supply is opened and the distributing pipes become filled with water, prior to the automatic opening of any of the sprinkler heads. Accordingly, when the latter do open there is a very prompt discharge of the fire extinguishing medium without loss of time, and without danger of the fire being aided or spread by the discharge.

I claim as my invention:

A fire protective system, having in combination a dry pipe system with dry pipe valve having an intermediate chamber; an alarm system; and conduit connections between the two systems including a conduit leading from the air side of the dry pipe valve and a second conduit leading from the intermediate chamber thereof; means controlling the first mentioned conduit comprising a releasing device actuated by a change of temperature of predetermined character and extent to open the entrance to said conduit, whereby air from the dry pipe system is admitted to the alarm system; a valve adapted to close said first mentioned conduit, actuated by liquid therein consequent upon the opening of the dry pipe valve; and a valve in the second conduit adapted to be closed by fiuid pressure in the first conduit, as when air is howing therein, and to be opened by pressure of liquid therein, entering from the intermediate chamber after opening of the dry pipe Valve.

BENJAMIN RICHARDS. 

